News / Science & Technology

    Research Suggests Prehistoric Man First Influenced Climate Change

    Early farmers' use of controlled forest burns, like this one in current-day Uganda, could have begun releasing climate changing gases into the atmosphere 8,000 years ago.
    Early farmers' use of controlled forest burns, like this one in current-day Uganda, could have begun releasing climate changing gases into the atmosphere 8,000 years ago.

    There is new evidence supporting a controversial theory that humans began changing the earth's climate with the development of agriculture some 8,000 years ago.

    In an article published in the journal Nature, researchers studying the theory say new data indicate that enormous amounts of earth-warming greenhouse gases released into the atmosphere by early farming activities helped ward off an impending ice age, and fostered the planet’s current relatively warm, stable climate.  

    A more commonly accepted theory suggests that man’s first major influence on the earth’s climate began in the 18th century, at the dawn of the industrial age.   

    Scientists say the new findings indicate that the earth was spared from another long deep freeze after the last Ice Age ended 11,000 years ago because of an unusual rise in atmospheric carbon dioxide and methane gas levels starting about 3,000 years later.  

    The increase coincided with the advent of farming practices - including the clearing and burning of forests, and maintaining large herds of livestock - that released more of those heat-trapping gases into the atmosphere.

    Prehistoric climate expert William Ruddiman of the University of Virginia first proposed the theory in 2003. He said the new findings supporting his hypothesis will be published in a series of papers later this year in a special issue of the journal The Holocene.

    Critics of the theory say human populations 8,000 years ago were too small to produce enough greenhouse gases to influence global climate change. And they suggest that other causes, including changes in the earth's orbit and a variety of natural events, could explain the unusual rise in greenhouse gases.

    Greenhouse gases are man-made and naturally-occurring gases that trap solar heat in the earth’s atmosphere.

    Most scientists now believe that modern man’s burning of fossil fuels and the clearing of forests over the past two centuries have intensified the so-called "Greenhouse Effect" and have caused a gradual warming of the earth's climate.

    You May Like

    Clinton, Trump and the 'Woman’s Card'

    Ask supporters of Democratic front-runner in US presidential campaign, and they’ll tell you Republican presidential candidate is playing a dangerous hand

    Russian Censorship Group Seeks Chinese Help to Better Control Internet

    At recent Safe Internet League forum in Moscow, speakers from both nations underscored desire for authorities to further limit and control information online

    Video Makeshift Pakistani School Helps Slum Kids

    Free classes in Islamabad park serve a few of the country’s nearly 25 million out-of-school youths; NGO cites ‘education crisis’

    This forum has been closed.
    Comments
         
    There are no comments in this forum. Be first and add one

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    Turkish Kurd Islamist Rally Stokes Tensionsi
    X
    April 29, 2016 12:28 AM
    In a sign of the rising power of Islamists in Turkey, more than 100,000 people recently gathered in Diyarbakir, the main city in Turkey’s predominantly Kurdish southeast, to mark the birthday of the Prophet Muhammad. The gathering highlighted tensions with the pro-secular Kurdish nationalist movement. Dorian Jones reports from Diyarbakir.
    Video

    Video Turkish Kurd Islamist Rally Stokes Tensions

    In a sign of the rising power of Islamists in Turkey, more than 100,000 people recently gathered in Diyarbakir, the main city in Turkey’s predominantly Kurdish southeast, to mark the birthday of the Prophet Muhammad. The gathering highlighted tensions with the pro-secular Kurdish nationalist movement. Dorian Jones reports from Diyarbakir.
    Video

    Video Pakistani School Helps Slum Kids

    Master Mohammad Ayub runs a makeshift school in a public park in Islamabad. Thousands of poor children have benefited from his services over the years, but, as VOA's Ayesha Tanzeem reports, roughly 25 million school-age youths don't get an education in Pakistan.
    Video

    Video Florida’s Weeki Wachee ‘Mermaids’ Make a Splash

    Since 1947, ‘mermaids’ have fascinated tourists at central Florida’s Weeki Wachee Springs State Park with their fluid movements and synchronized ballet. Performing underwater has its challenges, including cold temperatures and a steady current, as VOA’s Lin Yang and Joseph Mok report.
    Video

    Video Somali, African Union Forces Face Resurgent Al-Shabab

    The Islamic State terror group claimed its first attack in Somalia earlier this week, though the claim has not been verified by forces on the ground. Meanwhile, al-Shabab militants have stepped up their attacks as Somalia prepares for elections later this year. Henry Ridgwell reports there are growing frustrations among Somalia’s Western backers over the country’s slow progress in forming its own armed forces to establish security after 25 years of chaos.
    Video

    Video Bangladesh Targeted Killings Spark Wave of Fear

    People in Bangladesh’s capital are expressing deep concern over the brutal attacks that have killed secular blogger, and most recently a gay rights activist and an employee of the U.S. embassy. Xulhaz Mannan, an embassy protocol officer and the editor of the country’s only gay and transgender magazine Roopban; and his friend Mehboob Rabbi Tanoy, a gay rights activist, were hacked to death by five attackers in Mannan’s Dhaka home earlier this month.
    Video

    Video Documentary Tells Tale of Chernobyl Returnees

    Ukraine this week is marking the 30th anniversary of the world's worst nuclear accident, at the Chernobyl nuclear power plant. Soviet officials at first said little about the accident, but later evacuated a 2,600-square-kilometer "exclusion zone." Some people, though, came back. American directors Holly Morris and Anne Bogart created a documentary about this faithful and brave community. VOA's Tetiana Kharchenko reports from New York on "The Babushkas of Chernobyl." Carol Pearson narrates.
    Video

    Video Nigerians Feel Bite of Buhari Economic Policy

    Despite the global drop in the price of oil, Nigerian President Muhammadu Buhari has refused to allow the country's currency to devalue, leading to a shortage of foreign exchange. Chris Stein reports from Lagos businessmen and consumers are feeling the impact as the country deals with a severe fuel shortage.
    Video

    Video  Return to the Wild

    There’s a growing trend in the United States to let old or underused golf courses revert back to nature. But as Erika Celeste reports from one parcel in Grafton, Ohio, converting 39 hectares of land back to green space is a lot more complicated than just not mowing the fairway.
    Video

    Video West Urges Unity in Libya as Migrant Numbers Soar

    The Italian government says a NATO-led mission aimed at stemming the flow of migrants from Libya to Europe could be up and running by July. There are concerns that the number of migrants could soar as the route through Greece and the Balkans remains blocked. Western powers say the political chaos in Libya is being exploited by people smugglers — and they are pressuring rival groups to come together under the new unity government. VOA's Henry Ridgwell reports.
    Video

    Video Russia’s TV Rain Swims Against Tide in Sea of Kremlin Propaganda

    Russia’s media freedoms have been gradually eroded under President Vladimir Putin as his government has increased state ownership, influence, and restrictions on critical reporting. Television, where most Russians get their news, has been the main target and is now almost completely state controlled. But in the Russian capital, TV Rain stands out as an island in a sea of Kremlin propaganda.

    Special Report

    Adrift The Invisible African Diaspora